Arduino Micro - Unknown Device

I have a brand new micro that was working fine yesterday. Today I attempted to upload a new sketch to it and received an error. I assumed this was because I had something still listening to the COM port so stopped that and tried to upload again, but nothing happened. I tried resetting the Micro and now the Bootloader COM appears briefly and disappears. I get the following message, USB Device Not Recognized.

I've done a lot of searching online and none of the suggestions on "quickly" uploading a basic sketch while the bootloader COM appears resolve the issue. I got Blink sketch to give me an Uploaded message twice but still no change. Is the Micro now useless? Is there anyway to factory reset this? This is brand new and I'd hate to think it's that easy to make it useless but I can't find any way to get it working again in Device Manager as it was before. I've tried searching for an INF file to manually set the driver but haven't had any luck finding the right driver. I've also tried upgrading the AVR boards in Board Manager with no luck. Using IDE 1.6.7 on Windows 7 (x64).

Any help is greatly appreciated.

I tried resetting the Micro and now the Bootloader COM appears briefly and disappears.

So you pressed the reset button on the board? That just cycles power off then on. And what is bootloader COM? Never heard of that before. Do you mean COM port? Is the COM Port list under tools greyed out? If it is, it’s likely a driver issue.

So when pressing the reset button, it definitely resets. I get a "Arduino Micro Bootloader (COM15)" in Device Manager, then it quickly goes away. And COM14 which used to be able to used for programming never appears. Universal Serial Bus Controllers then shows "Unknown Device."

The COM port list in the IDE isn't greyed out because I have other devices plugged in, but COM15, appears and disappears from it as quickly as it does in Device Manager.

So if it's a driver issue, I'd think there'd be a way to solve this with finding the correct driver. Not sure how the driver would have been suddenly lost nor how to find it again. I could try uninstalling and reinstalling the Arduino IDE, not sure if this will fix it though, seems like the USB driver would be Windows side.

Never heard of it showing up in device manager then just disappears. Do you have anything connected to the board? Tried restarting the pc to see if its a driver corruption?

I have Arduino Micro clone with the CH340 chip (quite obvious when you look at the underside of the module) and in Windows 7 Pro 64-bit, I had to install the CH340 driver and it shows up as USB-SERIAL CH340 .

Well rebooting the machine failed. Plugging the Micro into another Windows PC failed. And uninstalling and reinstalling the Arduino IDE failed. Is it possible to fix it through FTDI programming?

Sorry FTDI is not what I meant... but I think since I have an AVRISP programmer at home I may have to try fixing this using the steps in documented at this site. This looks like it may be the answer. Still not sure how trying to upload a new sketch caused this, but we're past that now...

You can re load the boatloader with the programmer. Or just upload using the programmer. If you do though, it will erase the bootloader and will no longer be able to use USB until you burn the bootloader again.

I've already tried using the Arduino IDE to reburn the bootloader but get the following error:

Arduino: 1.6.7 (Windows 7), Board: "Arduino/Genuino Micro"

avrdude: usbdev_open(): did not find any USB device "usb"
Error while burning bootloader.

So I may be stuck having to use the ISP programming method. I'm lucky to have an AVRISP MkII programmer from Atmel at home, never used it though.

Just use the MKII. I have one and it's awesome.

Well I may be hosed. I spent hours last night trying to find the right bootloader and the process for uploading via ISP. I used an Atmel AVRISP MkII and tested using the Arduino IDE as well as Atmel Studio with no success in actually resolving the problem. I even tried uninstalling Atmel Studio because of reported issues with Jungo drivers with no success.
I'm also unable to locate any documentation on what the fuses and lock bits are supposed to be set to for the Micro using the Atmega32U4.
The best I can do is have the device seen as an Atmel device in Device Manager, but this never appears as a COM or USB port for Arduino IDE to see and use again.

It really frustrates me that this is so easy to mess up and so difficult to fix. A $25 waste and no way to contact Arduino directly to complain about it. If we're going to spend double the amount for true Arduino products over their cheaper knock-off counter parts the least they could do is offer better support on how to fix things like this rather than leaving everyone to forums hoping someone else can help.

the least they could do is offer better support on how to fix things like this rather than leaving everyone to forums hoping someone else can help.

Well I may be hosed.

Ok, time to fix it now. You are most likely not hosed.

Open the IDE and go into the Preferences and put a checkmark on show verbose output during upload.
Go to the Tools, Board menu and select Arduino/Genuino Micro
Go to the Tools, Programmer menu and select AVRISP MkII

Connect the AVRISP MkII to the Micro's ISCP header.
Connect the AVRISP MkII via USB to the computer.
Connect the Micro to a power supply or USB to computer for power.

Go to the Tools menu and select Burn Bootloader.
At the bottom of the IDE window you will see the 2 avrdude commands that the IDE attempts to run, and the results. Check that they both end without error. If the second avrdude command ends with error, copy and paste the second command in a command prompt window and run it manually. Verify it works ok the second attempt by looking at the output of the command line window.

Disconnect everything.

Connect the Micro to your computer and verify it is restored.